Studies On Synthesis And Applications Of Benzoxadiazole Based Small Molecule Fluorescent Probes

Due to the good sensitivity and selectivity, low detection limit and real-time imaging, fluorescent probe has been developing rapidly in recent years in areas of modern biology, chemistry biology, pharmacy and medical. In a variety of heavy metal ions, Hg2+ can cause severe damage to the central nervous system, the excessive exposure to Hg2+ can also lead to dysfunctions of the cells, kidney and stomach. Therefore, developing an effective and sensitive method to selectively detect Hg2+ is of great significance. In the first part of the work, based on the benzoxadiazole fluorophores, we design and synthesiz a ratio fluorescent probes H-1 for mercury. In this work, the coordination reaction of mercury and the probe II-1 may induce remarkable changes of the intramolecular conjugated system and the changes in optical properties. And the morpholino group may be targeting the accurate target in subcellular organelles lysosomes. Hydrogen sulfide is considered as the third signaling molecule in vivo as well as nitric oxide and carbon monoxide. HtS plays some important roles in various physiological processes and pathological processes in vivo. Therefore, developing a highly selective and sensitive method that can detect H2S and be applied in the biological system is very significant. In the second part of the work, based on the dansyl chloride fluorophore, we designed and synthesized a turn-on fluorescent probe III-l for hydrogen sulfide. In this work, the nucleophilic reaction of hydrogen sulfide and the probe III-l may induce remarkable changes in optical properties. Specific work content is as follows:1.This paper summarizes the recent progress in the development of probes for detection of Hg’and H2S.2.4-Chloro-7-nitrobenzo-2-oxa-l,3-diazole and 4-(2-Aminoethyl)morpholine as starting material, we designed and synthesized a fluorescent probe for mercury. The related structures were characterized by’HNMR and MS. Studies have shown that the probe II-l can detect Hg2+with high selectivity and can probing Hg2+in the cell level. Coordination reaction of mercury and the probe II-l may induce remarkable changes of the intramolecular conjugated system and PET effect, which reflects signal change of the absorption spectra and fluorescence emission spectra.3.Dansyl chloride, piperazine and 4-Chloro-7-nitrobenzo-2-oxa-l,3-diazole as starting material, we designed and synthesized a fluorescent probe for hydrogen sulfide. The related structures were characterized by’HNMR and MS. Studies have shown that the probe III-l can detect H^S with high selectivity and can probing H2S in the cell level. Nucleophilic reaction of hydrogen sulfide and the probe III-1 may induce remarkable changes of the intramolecular conjugated system and PET effect, which reflects signal change of the absorption spectra and fluorescence emission spectra.